Many older phones support mobile broadband sharing to computers through Bluetooth Dial-Up Networking (DUN). When the phone is paired with a computer, the computer may request that the phone provide a virtual serial port, and then the computer treats that virtual serial port as a normal mobile broadband connection card, sending AT commands and starting PPP.

Enhanced functionality in the gnome-bluetooth plugin allows users to set up their network connection with a few clicks, after which the phone and the network connection are available from the nm-applet menu.
Possible related feature pages: